Can Humans Reproduce In Zero-Gravity?

New research details biological difficulties in mammalian reproduction and development in space. Teruhiko Wakayama and his colleagues at the RIKEN Center for Developmental Biology in Kobe used a 3D clinostat to conduct experiments with mouse sperm and ova in a microgravity environment.

The 3D clinostat apparatus uses rotation in all three dimensions to enable cell culture experiments under conditions that recreate zero-gravity. This allows research on the earliest stages of embryonic development in an environment that simulates space travel.

They performed in vitro fertilization (IVF) experiments with mouse sperm and ova, both within the clinostat and at regular gravity (1G), and determine that microgravity had minimal effects on fertilization. It may prove detrimental to subsequent development, however. Microgravity-cultured embryos successfully reached the two-cell stage and yielded viable offspring upon implantation into female mice, but at a significantly lower rate than their 1G counterparts. The researchers observed more severe negative effects when embryos were transplanted following longer culture periods in the clinostat.

Microgravity led to an overall reduction in the rate of blastocyst formation after 96 hours of culture, and closer examination of these blastocysts revealed that the differentiation of embryonic cells into trophectodermóthe tissue that nourishes the embryo and ultimately contributes to placenta formationówas markedly impaired.

This finding casts into doubt the science fictional notion that human beings can survive in zero gravity or in the microgravity environment of large asteroids (Belters, I'm talking to you!).